| 摘要 |
PURPOSE:To make an optical output constant without reference to fluctuations of temperature, a secular change, and variation in background light, by providing a background light breaker to an optical transmitter used for optical space communication, and thus cutting the background light. CONSTITUTION:A light emitting element 10 placed at the focal point of a lens 11 is driven by a light-emitting-element driving circuit 9 to generate an optical output according to an input signal. The optical output is collimated through the lens 11 and transmitted to a reception sie, but part of the optical output is converted into an electric signal by a photodetecting element 13 placed where the main beam of the light emitting element is not disturbed and then amplified by an amplifier 14 before being applied to the driving circuit 9. Since the influence of background light is removed from the photodetecting element 13 by a background light breaker 12, the output of this optical transmitter is made constant without reference to fluctuations of temperature, a secular change, and variation in background light. |
